The Salience Of Lower-order Features In Highly Self-similar Wallpaper Groups

Open Access
Author:
Vedak, Shivam
Area of Honors:
Interdisciplinary in Biology and Psychology
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • Rick Owen Gilmore, Thesis Supervisor
  • Dr Gong Chen, Honors Advisor
  • Rick R Jacobs, Honors Advisor
Keywords:
  • symmetry
  • perception
  • vision
  • wallpaper group
  • isometry
  • regularity
  • pattern
  • geometry
  • group theory
Abstract:
There exists an abundance of visual symmetry within our environment. Yet research on human perception has almost exclusively been limited to studies of a single type of symmetry— two-fold reflection—leaving uncertainty about human perceptual sensitivity to the other types of symmetry as derived from the mathematics of Group Theory. Clarke et al. (2011) found that five of the seventeen wallpaper groups—P1, P3M1, P31M, P6, and P6M—have a high degree of self-similarity, as determined by the frequency with which participants grouped random-dot noise representations of the same wallpaper group together. The current study attempts to replicate Clarke et al. (2011) in a limited form. Here, we sought to understand the salience of lower-order features within each of five wallpaper groups, and concordantly, their impact on symmetry detection. Adult participants were presented with twenty exemplars of each of the five aforementioned wallpaper groups and instructed to sort them into as many subsets as they wished based on any criteria they saw appropriate. Participants were then surveyed on the methods they used to classify these images. Analysis suggest several factors—including contrast and presence of salient secondary structures—influence the detection of symmetry in wallpaper groups.